1. Field of the Invention
The present invention generally relates to the field of video analysis, and particularly relates to a method, a device, and a computer-readable medium for detecting at least one object in a display area.
2. Description of the Related Art
In a presentation or a meeting, a device such as a projection screen or a wide-screen display is usually used for displaying relevant contents. In a case where a projection system is taken as an example, intelligent interaction with projection contents is strongly required as projection devices are in widespread use in offices. In general, a user adopts a computer connected to the projection device to realize the interaction. However, in order to realize the interaction, the user needs to walk back and forth between the computer and the projection device so as to control the projection contents, for example, to turn a page. Although it is possible to utilize a USB device to achieve remote page turning, this kind of function is too simple; as a result, the requirement of complicated interaction cannot be satisfied.
At present, it is possible to simulate a touch panel by employing video analysis according to the most recent development of computer vision. In particular, if a presenter puts (inserts) an object such as his finger, a rod, etc. into a display area of a projection screen, then it is possible to calculate positional information of the object by using video analysis; the positional information is continuously fed back to a computer so as to able to use the positional information of the object to trigger a predetermined event. Since the inserted object may be influenced by continuous and unpredictable projection contents, it is difficult to carry out accurate and real time positioning of the inserted object by utilizing this technique.
In the below cited reference No. 1, a system in which an infrared light source is used to send infrared light toward a human hand is disclosed. However, since hardware configurations in the system are complicated, the system may not be applied to a general presentation environment.
In the below cited reference No. 2, a hand gesture recognition system is disclosed in which a dedicated projector able to alternately send visible light and infrared light is adopted. However, it may cost much money to buy the dedicated projector for a user.
Furthermore, in the below cited reference No. 3, a method of achieving perceptually seamless multi-projector displays is disclosed. However, in an area with low brightness, noise may be introduced in a predictable image when using the method.
Therefore a method and a device by which at least one inserted object in a display area such as a projection screen may be detected conveniently, easily, accurately, timely, and relatively cheaply are desirable.    Cited Reference No. 1: US Patent Application Publication NO. 2009/0103780 A1    Cited Reference No. 2: US Patent Application Publication NO. 2009/0115721 A1    Cited Reference No. 3: Aditi Majumder, “A Practical Framework to Achieve Perceptually Seamless Multi-Projector Displays” (Doctor Thesis, 2003)